Clinical laboratory instruments are utilized for analysis of body fluids, such as but not limited to, whole blood, serum or plasma, in order to diagnose various conditions. In order to utilize these instruments, a broad range of reagents are necessary. Because these reagents contain nutrients for microorganisms, microbial growth is frequently a problem, especially for commercially distributed products, which often require months or years of shelf life in order to be commercially practical products.
One subcategory of such instruments and chemicals are those which are used in the critical care area, where the analytical results must be obtained quickly. These are used to measure items such as but not limited to, the concentrations in the blood of such components as carbon dioxide, oxygen, total hemoglobin, sodium, potassium, chloride, calcium, magnesium, lactate or glucose, as well as physical properties such as pH. In this environment, it is especially important that the systems work properly, because of the need for personnel to quickly make decisions regarding diagnosis and treatment of the patient. Therefore, microbicidal compositions are typically included in reagents utilized with critical care instruments to both keep the reagents uncontaminated during manufacturing and particularly to keep the instrument and sensors free of contamination during their use. Microbial contamination of an instrument will cause erroneous results, while microbial contamination of the reagent will cause the reagent to be unstable and potentially compromise the instrument.
There are presently various microbicidal compositions commercially available that are compatible with most prior art reagents and instruments. One example of a microbicidal composition utilized in such reagents is disclosed in U.S. Pat. No. 5,464,850, issued to Voo et al., on Nov. 7, 1995. However, these current microbicidal compositions are incompatible with enzyme based sensors; thus, the development of enzyme based sensors for use in these instruments requires that new and improved microbicidal compositions that are efficacious and do not adversely affect said enzymes be identified.
Thus, a need exists for new and improved microbicidal compositions that overcome the disadvantages and defects of the prior art compositions. It is to such compositions, and methods of producing and using same, that the presently disclosed and claimed inventive concept(s) is directed.